We report the first searches for charged-lepton-flavor violation in decays of χ₁₉ (1P) (J=0, 1, and 2) to a pair of charged leptons using 158 million Υ (2S) decays collected with the Belle detector in e^+e^- collisions at the KEKB collider. No significant signal is observed, and we set upper limits on the branching fractions for χ₁₉ (1P) decays to e^μ^ at the level of 10^-6 and to e^τ^ or μ^τ^ at the level of 10^-5. Limits on χ₁₀ (1P) decays are translated into bounds on the corresponding Wilson coefficients of scalar operators that mediate charged-lepton-flavor violation.
Abumusabh et al. (Thu,) studied this question.